Added support for controlling hardware gain amps on input ports
using a volume control mixer with a mux selecting the port being controlled.
Signed-off-by: NMatthew Ranostay <mranostay@embeddedalley.com>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>
Signed-off-by: NJaroslav Kysela <perex@perex.cz>